Bug 1462791 - Add helper function for VCS checkout on generic-worker; r=dustin

This functionality was implemented at least 3 times. Let's consolidate
it to a central function.

Returning multiple command strings is kind of funky. I preserved
existing behavior and mozharness jobs are the only ones printing the
forensic logging. We should probably move this logging into
robustcheckout so we don't need to involve taskgraph with this. But
that can be deferred to another day.

MozReview-Commit-ID: I2LglJvfI6

--HG--
extra : rebase_source : 7cb413694aee4e46a6522febe9daa4b73b5307ca
extra : source : 096d7d374af427ee950c7a550878781eebad4135

taskcluster/taskgraph/transforms/job/common.py

@@ -132,6 +132,34 @@ def support_vcs_checkout(config, job, taskdesc, sparse=False):
         taskdesc['worker']['taskcluster-proxy'] = True
 
 
+def generic_worker_hg_commands(base_repo, head_repo, head_rev, path):
+    """Obtain commands needed to obtain a Mercurial checkout on generic-worker.
+
+    Returns two command strings. One performs the checkout. Another logs.
+    """
+    args = [
+        r'"c:\Program Files\Mercurial\hg.exe"',
+        'robustcheckout',
+        '--sharebase', r'y:\hg-shared',
+        '--purge',
+        '--upstream', base_repo,
+        '--revision', head_rev,
+        head_repo,
+        path,
+    ]
+
+    logging_args = [
+        b":: TinderboxPrint:<a href={source_repo}/rev/{revision} "
+        b"title='Built from {repo_name} revision {revision}'>{revision}</a>"
+        b"\n".format(
+            revision=head_rev,
+            source_repo=head_repo,
+            repo_name=head_repo.split('/')[-1]),
+    ]
+
+    return ' '.join(args), ' '.join(logging_args)
+
+
 def docker_worker_setup_secrets(config, job, taskdesc):
     """Set up access to secrets via taskcluster-proxy.  The value of
     run['secrets'] should be a boolean or a list of secret names that

taskcluster/taskgraph/transforms/job/mozharness.py

@@ -24,6 +24,7 @@ from taskgraph.transforms.job.common import (
     docker_worker_add_artifacts,
     docker_worker_add_tooltool,
     generic_worker_add_artifacts,
+    generic_worker_hg_commands,
     support_vcs_checkout,
 )
 
@@ -292,43 +293,20 @@ def mozharness_on_generic_worker(config, job, taskdesc):
         mh_command.append('--custom-build-variant')
         mh_command.append(run['custom-build-variant-cfg'])
 
-    def checkout_repo(base_repo, head_repo, head_rev, path):
-        hg_command = ['"c:\\Program Files\\Mercurial\\hg.exe"']
-        hg_command.append('robustcheckout')
-        hg_command.extend(['--sharebase', 'y:\\hg-shared'])
-        hg_command.append('--purge')
-        hg_command.extend(['--upstream', base_repo])
-        hg_command.extend(['--revision', head_rev])
-        hg_command.append(head_repo)
-        hg_command.append(path)
-
-        logging_command = [
-            b":: TinderboxPrint:<a href={source_repo}/rev/{revision} "
-            b"title='Built from {repo_name} revision {revision}'>{revision}</a>\n".format(
-                revision=head_rev,
-                source_repo=head_repo,
-                repo_name=head_repo.split('/')[-1],
-            )]
-
-        return [
-            ' '.join(hg_command),
-            ' '.join(logging_command),
-        ]
-
-    hg_commands = checkout_repo(
+    hg_commands = generic_worker_hg_commands(
         base_repo=env['GECKO_BASE_REPOSITORY'],
         head_repo=env['GECKO_HEAD_REPOSITORY'],
         head_rev=env['GECKO_HEAD_REV'],
-        path='.\\build\\src')
+        path=r'.\build\src',
+    )
 
     if run['comm-checkout']:
         hg_commands.extend(
-            checkout_repo(
+            generic_worker_hg_commands(
                 base_repo=env['COMM_BASE_REPOSITORY'],
                 head_repo=env['COMM_HEAD_REPOSITORY'],
                 head_rev=env['COMM_HEAD_REV'],
-                path='.\\build\\src\\comm')
-        )
+                path=r'.\build\src\comm'))
 
     worker['command'] = []
     if taskdesc.get('needs-sccache'):

taskcluster/taskgraph/transforms/job/spidermonkey.py

@@ -14,6 +14,7 @@ from taskgraph.transforms.job import run_job_using
 from taskgraph.transforms.job.common import (
     docker_worker_add_artifacts,
     generic_worker_add_artifacts,
+    generic_worker_hg_commands,
     docker_worker_add_gecko_vcs_env_vars,
     docker_worker_add_tooltool,
     support_vcs_checkout,
@@ -115,20 +116,17 @@ def generic_worker_spidermonkey(config, job, taskdesc):
         # Don't allow untested configurations yet
         raise Exception("spidermonkey-rust-bindings is not a supported configuration")
 
-    hg_command = ['"c:\\Program Files\\Mercurial\\hg.exe"']
-    hg_command.append('robustcheckout')
-    hg_command.extend(['--sharebase', 'y:\\hg-shared'])
-    hg_command.append('--purge')
-    hg_command.extend(['--upstream', 'https://hg.mozilla.org/mozilla-unified'])
-    hg_command.extend(['--revision', env['GECKO_HEAD_REV']])
-    hg_command.append(env['GECKO_HEAD_REPOSITORY'])
-    hg_command.append('.\\src')
+    hg_command = generic_worker_hg_commands(
+        'https://hg.mozilla.org/mozilla-unified',
+        env['GECKO_HEAD_REPOSITORY'],
+        env['GECKO_HEAD_REV'],
+        r'.\src',
+    )[0]
 
     command = ['c:\\mozilla-build\\msys\\bin\\bash.exe '  # string concat
                '"./src/taskcluster/scripts/builder/%s"' % script]
 
-    worker['command'] = []
-    worker['command'].extend([
-        ' '.join(hg_command),
-        ' '.join(command)
-    ])
+    worker['command'] = [
+        hg_command,
+        ' '.join(command),
+    ]

taskcluster/taskgraph/transforms/job/toolchain.py

@@ -17,6 +17,7 @@ from taskgraph.transforms.job.common import (
     docker_worker_add_gecko_vcs_env_vars,
     docker_worker_add_artifacts,
     docker_worker_add_tooltool,
+    generic_worker_hg_commands,
     support_vcs_checkout,
 )
 from taskgraph.util.hash import hash_paths
@@ -205,15 +206,11 @@ def windows_toolchain(config, job, taskdesc):
         'MOZ_AUTOMATION': '1',
     })
 
-    hg = r'c:\Program Files\Mercurial\hg.exe'
-    hg_command = ['"{}"'.format(hg)]
-    hg_command.append('robustcheckout')
-    hg_command.extend(['--sharebase', 'y:\\hg-shared'])
-    hg_command.append('--purge')
-    hg_command.extend(['--upstream', 'https://hg.mozilla.org/mozilla-unified'])
-    hg_command.extend(['--revision', '%GECKO_HEAD_REV%'])
-    hg_command.append('%GECKO_HEAD_REPOSITORY%')
-    hg_command.append('.\\build\\src')
+    hg_command = generic_worker_hg_commands(
+        'https://hg.mozilla.org/mozilla-unified',
+        env['GECKO_HEAD_REPOSITORY'],
+        env['GECKO_HEAD_REV'],
+        r'.\build\src')[0]
 
     # Use `mach` to invoke python scripts so in-tree libraries are available.
     if run['script'].endswith('.py'):
@@ -225,7 +222,7 @@ def windows_toolchain(config, job, taskdesc):
 
     bash = r'c:\mozilla-build\msys\bin\bash'
     worker['command'] = [
-        ' '.join(hg_command),
+        hg_command,
         # do something intelligent.
         r'{} build/src/taskcluster/scripts/misc/{}{}'.format(
             bash, run['script'], args)